Rinnai RX199iN Condensing Smart Sense Tankless Water Heater Alternatives: 6 Similar Picks Compared
As an Amazon Associate we earn from qualifying purchases. Links on this page are affiliate links.
The rinnai rx199in condensing smart sense tankless water heater delivers 11.1 GPM flow with dual-fuel flexibility for indoor or outdoor use. Its condensing design achieves a UEF of .98, making it efficient for large households needing simultaneous hot water. You might choose an alternative if you require a smaller footprint, a different fuel source like propane only, or a lower flow rate for smaller homes. Some buyers may also prefer units that include smart controls without extra modules or specific installation constraints like elevation limits.
This list compares 6 similar picks based on overlapping specifications such as flow rate, venting type, and fuel compatibility. We selected these models because they share key technical traits with the original unit, including condensing technology and natural gas operation. Each option offers distinct advantages in size, efficiency, or intended use. You can compare these alternatives to find a heater that better fits your specific spatial or performance needs without compromising on core functionality.
Our top pick: Rinnai 11.1 GPM Condensing Dual-Fuel Water Heater.
How alternatives compare to Rinnai RX199iN
Ranein 5.1 GPM Condensing Natural Gas Water Heater
The Ranein RH12KG-C-NG offers a 5.1 GPM flow rate, which is significantly lower than the Rinnai RX199iN’s 11.1 GPM. It weighs only 26 pounds, making it much lighter and easier to handle than the 55-pound Rinnai unit. Its compact dimensions of 14.2 by 14.2 by 22 inches fit better in tight indoor spaces. This model uses natural gas and condensing venting, similar to the Rinnai. You should choose this alternative if you have a smaller household with low elevation needs and do not require high simultaneous flow rates. It sacrifices capacity for a smaller physical footprint and lower weight.
VancEpic 5.1 GPM Propane Condensing Water Heater
The VancEpic RH12KG-C-LPG runs on propane instead of the Rinnai’s dual-fuel capability. It provides 5.1 GPM, which is less than half the flow of the Rinnai RX199iN. The unit is extremely compact, measuring only 9.25 inches in height, compared to the Rinnai’s 30.1 inches. It weighs no more than 26 pounds, far lighter than the 55-pound Rinnai. This model is designed strictly for indoor use with condensing venting. Pick this alternative if you rely on propane and have limited vertical space. You give up high flow capacity and dual-fuel flexibility for a very small, propane-specific indoor solution.
Rinnai I-SERIES Plus Condensing Combi Boiler
The Rinnai IP175199C is a combi boiler, not just a water heater. It delivers 175K BTU for space heating and 199K BTU for domestic hot water, offering dual functionality the RX199iN lacks. It is taller at 45.3 inches and heavier at 79.4 pounds than the 30.1-inch, 55-pound Rinnai water heater. The width is similar at 19.5 inches. This unit is for homes needing both space heating and hot water. Choose this if you want a single unit for both needs. You accept a larger size and higher weight for the added benefit of integrated space heating capabilities alongside high-efficiency condensing venting.
Thermomate 5.28 GPM Indoor Natural Gas
The Thermomate CZ480NG provides 5.28 GPM, which is less than the Rinnai RX199iN’s 11.1 GPM. It is a natural gas unit with condensing venting, similar to the Rinnai. The Thermomate is much smaller, weighing only 26 pounds compared to the Rinnai’s 55 pounds. Its dimensions are 13.8 by 13.8 by 21.7 inches, making it more compact than the Rinnai’s 30.1 by 18.5 by 30.1 inches. This model is for indoor use only. Select this alternative if you prioritize a smaller footprint and digital control over high flow rates. You trade significant flow capacity for a lighter, more compact indoor unit.
Rheem Prestige 11 GPM Condensing Water Heater
The Rheem RTGH-RH11DVLN offers 11 GPM, which is nearly identical to the Rinnai RX199iN’s 11.1 GPM. It is a natural gas condensing unit designed for indoor use, whereas the Rinnai supports outdoor installation. The Rheem is slightly lighter and more compact, measuring 14.8 by 17.3 by 28.7 inches. It lacks the dual-fuel flexibility of the Rinnai. Choose this alternative if you need high flow rates but are restricted to indoor natural gas installation. You gain a similar flow capacity in a smaller package but lose the ability to use propane or install the unit outdoors.
Rinnai RU160eN 9 GPM Outdoor Natural Gas
The Rinnai RU160eN delivers 9 GPM, which is lower than the RX199iN’s 11.1 GPM. It is designed strictly for outdoor installation, unlike the RX199iN which works indoors or outdoors. It weighs 71 pounds, heavier than the 55-pound RX199iN. The dimensions are 22.1 by 14.8 by 33.9 inches, making it taller but narrower. This model uses natural gas and condensing venting. Pick this alternative if you have outdoor space and prefer a dedicated outdoor unit. You sacrifice some flow rate and indoor versatility for a model optimized for exterior mounting and outdoor durability.
Quick picks
Our 7 picks
Rinnai 11.1 GPM Condensing Dual-Fuel Water Heater
Best for: large households needing high flow rates
- Fuel Type
- Natural Gas or Propane
- Flow Rate
- 11.1 GPM
- BTU
- 199k BTU
- Installation Location
- Indoor/Outdoor
- Venting Type
- Condensing
- Dimensions
- 30.1 × 18.5 × 30.1 inches
View on Amazon: Rinnai 11.1 GPM Condensing Dual-Fuel Water Heater Affiliate link
The Rinnai RX199iN delivers 11.1 GPM of hot water for up to seven fixtures. It runs on natural gas or propane and works indoors or outdoors. The unit measures 30.1 by 18.5 by 30.1 inches and weighs 55 pounds. It features a condensing design with a .98 UEF. You get a 15-year heat exchanger warranty if registered. This model suits homes needing high flow rates and flexible installation options.
Pros
- 11.1 GPM flow rate supports seven fixtures simultaneously
- Condensing design achieves a .98 UEF efficiency rating
- Versa Vent allows indoor or outdoor installation
- Smart Sense gas control works with propane or natural gas
Cons
- WiFi control requires a separate Controlr module
- Professional installation is strongly recommended
- Labor warranty drops to one year if not registered within 90 days
Good fit if
- You need high flow for multiple bathrooms
- You want flexible indoor or outdoor placement
- You prefer propane or natural gas fuel
Skip if
- You want built-in WiFi connectivity
- You prefer a smaller footprint
- You plan to install it yourself
Verdict: Rinnai RX199iN 11.1 GPM Condensing Heater offers high capacity and efficiency for large homes. It fits buyers who need flexible venting and dual fuel options without extra smart hardware.
Ranein 5.1 GPM Condensing Natural Gas Water Heater
Best for: Indoor multi-bathroom homes with low elevation
- Fuel Type
- Natural Gas
- Flow Rate
- 5.1 GPM
- BTU
- 120,000 BTU
- Voltage
- 120V
- Temperature Control
- 95°F–149°F, ±1°F
- Certification
- ANSI Z21.10.3
View on Amazon: Ranein 5.1 GPM Condensing Natural Gas Water Heater Affiliate link
The Ranein RH12KG-C-NG delivers 5.1 GPM at 120,000 BTU using natural gas. Its condensing technology recycles exhaust heat to improve efficiency. You get precise temperature control from 95°F to 149°F with ±1°F accuracy. The unit includes an LED touchscreen and four preset modes. It fits 2-3 bathrooms and measures 22 x 14.2 x 6.4 inches. Professional installation is recommended.
Pros
- 5.1 GPM flow rate for multiple fixtures
- Condensing technology for up to 20% gas savings
- Precise 95°F to 149°F temperature control
- Includes Category III venting and drain kit
Cons
- Limited to 120V electrical connection
- Not rated for elevations above 2,000 ft
- Requires professional installation for safety
Good fit if
- You need a condensing unit for indoor installation
- You want precise temperature settings for bathtubs
- You have a 120V outlet near the unit
Skip if
- You live above 2,000 ft elevation
- You require propane fuel options only
- You need a DIY-friendly plug-and-play setup
Verdict: The Ranein 5.1 GPM Condensing Gas Heater suits homes needing efficient indoor heating with precise temperature control. It fits well where professional installation is already planned and elevation is low.
VancEpic 5.1 GPM Propane Condensing Water Heater
Best for: Small propane-powered indoor installations
- Fuel Type
- Propane
- Flow Rate
- 5.1 GPM
- BTU
- 120,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- 95°F to 149°F
- Dimensions
- 9.25 x 20.2 x 20.2 inches
View on Amazon: VancEpic 5.1 GPM Propane Condensing Water Heater Affiliate link
This VancEpic unit delivers 5.1 GPM at 120,000 BTU using propane. It uses condensing technology to capture exhaust heat, improving efficiency for indoor installation. The digital display lets you set temperatures between 95°F and 149°F. It includes anti-freeze protection and a condensate drain kit. This model suits small homes or apartments needing reliable on-demand hot water.
Pros
- 5.1 GPM flow rate for multiple fixtures
- 120,000 BTU propane output
- Digital LED display with temperature control
- Integrated anti-freeze function
Cons
- Propane fuel type limits placement options
- Indoor installation only
- 2-year limited warranty is shorter than competitors
Good fit if
- You need a compact unit for a small home
- You have existing propane gas lines
- You want condensing efficiency for lower gas consumption
Skip if
- You require natural gas compatibility
- You need outdoor installation capability
- You want a longer warranty period
Verdict: VancEpic 5.1 GPM Propane Condensing Heater fits propane users in small spaces. It offers solid flow rates and efficiency but lacks the warranty length of top picks.
Rinnai I-SERIES Plus Condensing Combi Boiler
Best for: Combined space heating and hot water needs
- Fuel Type
- Natural Gas, Propane
- Installation Location
- Indoor
- Dimensions
- 45.3 x 19.5 x 19.5 in
- Use
- Commercial, Boiler
- Venting Type
- Condensing
- Weight
- 79.4 pounds
View on Amazon: Rinnai I-SERIES Plus Condensing Combi Boiler Affiliate link
This Rinnai unit combines a tankless water heater with a space heating boiler. It delivers 175,000 BTU for home heating and 199,000 BTU for domestic hot water. The 96% AFUE rating ensures high energy efficiency for both functions. Smart Connect Wi-Fi and Smart Sense Gas Valve technology allow for precise control. It is designed for indoor installation and supports common venting for multiple units.
Pros
- Dual function provides both space heating and instant hot water
- 96% AFUE rating for high energy efficiency
- Smart Connect Wi-Fi enables remote management
- 175,000 BTU heating capacity with 199,000 BTU for DHW
Cons
- Large physical footprint at 45.3 inches tall
- Heavier build at 79.4 pounds
- Labor warranty defaults to 1-year if not registered within 90 days
Good fit if
- You need a single appliance for both space heating and hot water
- You want high efficiency with a 96% AFUE rating
- You require Wi-Fi connectivity for system control
Skip if
- You only need a dedicated water heater without space heating
- You have limited vertical clearance for a 45.3-inch unit
- You prefer a lighter unit under 50 pounds
Verdict: Rinnai I-SERIES Plus 175K BTU Combi Boiler suits homes needing combined heating and hot water with high efficiency. It fits users who value smart controls and can accommodate its size and weight.
Thermomate 5.28 GPM Indoor Natural Gas
Best for: indoor homes needing high flow and efficiency
- Fuel Type
- Natural Gas
- Flow Rate
- Up to 6 GPM
- BTU
- 114,000 BTU
- Installation Location
- Indoor
- Voltage
- 120V
- Temperature Control
- 90°F to 140°F
View on Amazon: Thermomate 5.28 GPM Indoor Natural Gas Affiliate link
The ThermoMate CZ480NG is a natural gas condensing unit delivering 5.28 GPM at 114,000 BTU. Its dual heat exchanger achieves 0.86 UEF efficiency. The 3.5-inch LED touchscreen allows precise temperature control from 90°F to 140°F. It includes eight safety protections and auto frost protection. This compact 26-pound unit fits indoor spaces well. It suits busy households needing simultaneous hot water.
Pros
- 5.28 GPM flow rate supports two showers
- 0.86 UEF efficiency with dual heat exchanger
- 3.5-inch LED touchscreen for easy monitoring
- Eight integrated safety protections
- Compact 21-inch height saves space
Cons
- Produces acidic condensate requiring neutralization
- 120V power cord limits placement options
- No smart home app integration listed
Good fit if
- You need high flow for multiple bathrooms
- You want precise digital temperature control
- You have indoor space for compact units
Skip if
- You require outdoor installation only
- You prefer propane fuel exclusively
- You want a non-condensing unit
Verdict: ThermoMate CZ480NG 5.28 GPM Condensing Heater offers strong efficiency and flow for indoor use. It fits homes prioritizing digital control and compact size over smart connectivity.
Rheem Prestige 11 GPM Condensing Water Heater
Best for: high-flow indoor households
- Fuel Type
- Natural Gas
- Flow Rate
- 11.0 GPM
- Installation Location
- Indoor
- Dimensions
- 28.7 x 17.3 x 14.8 inches
- Venting Type
- Condensing
View on Amazon: Rheem Prestige 11 GPM Condensing Water Heater Affiliate link
This Rheem unit delivers 11.0 GPM of hot water using natural gas. It features condensing technology for high efficiency and includes built-in recirculation. The Auto-Learn programming tracks usage patterns to optimize performance. Its compact design fits indoor spaces well. You will appreciate the integrated leak detection that shuts down the unit if a problem arises. This model suits large households needing steady flow.
Pros
- 11.0 GPM flow rate for high demand
- Built-in recirculation for instant hot water
- Auto-Learn programming optimizes usage patterns
- Water and gas leak detection safety feature
Cons
- Indoor installation only
- Larger physical footprint than smaller units
- No remote control mentioned in specifications
Good fit if
- You need a high flow rate for multiple bathrooms
- You want built-in recirculation without extra parts
- You are installing in an indoor utility space
Skip if
- You require outdoor installation capability
- You need propane fuel compatibility
- You have limited space for a larger unit
Verdict: Rheem Prestige 11 GPM Natural Gas provides robust flow for busy homes. It fits users who prioritize high capacity and smart programming over compact size.
Rinnai RU160eN 9 GPM Outdoor Natural Gas
Best for: High-flow outdoor whole-home hot water
- Fuel Type
- Natural Gas
- Flow Rate
- 9 GPM
- Installation Location
- Outdoor
- Dimensions
- 33.9 x 14.8 x 22.1 inches
- Venting Type
- Condensing
- Weight
- 71 pounds
View on Amazon: Rinnai RU160eN 9 GPM Outdoor Natural Gas Affiliate link
This Rinnai RU160eN is a condensing tankless water heater designed for outdoor installation. It delivers a flow rate of 9 GPM on natural gas, supporting up to six simultaneous appliances. The unit measures 33.9 x 14.8 x 22.1 inches and weighs 71 pounds. It carries an ENERGY STAR qualification with a Uniform Energy Factor of 0.95. You should choose this model if you need high-volume hot water for an outdoor setup.
Pros
- 9 GPM flow rate for whole-home use
- Condensing design for energy efficiency
- Rated for outdoor installation
- 15-year heat exchanger warranty
Cons
- Requires outdoor mounting only
- WiFi module sold separately
- Heavier than indoor units
Good fit if
- You need high flow for multiple outlets
- You have outdoor space for installation
- You want ENERGY STAR efficiency
Skip if
- You require indoor installation
- You need propane fuel
- You want built-in WiFi
Verdict: Rinnai RU160eN 9 GPM Outdoor Gas Heater is a high-capacity outdoor unit for homes needing six simultaneous fixtures. It suits buyers with outdoor space who prioritize flow rate over compact indoor footprint.
Specifications side by side
| Spec | Rinnai 11.1 GPM Condensing Dual-Fuel Water Heater | Ranein 5.1 GPM Condensing Natural Gas Water Heater | VancEpic 5.1 GPM Propane Condensing Water Heater | Rinnai I-SERIES Plus Condensing Combi Boiler | Thermomate 5.28 GPM Indoor Natural Gas | Rheem Prestige 11 GPM Condensing Water Heater | Rinnai RU160eN 9 GPM Outdoor Natural Gas |
|---|---|---|---|---|---|---|---|
| Fuel Type | Natural Gas or Propane | Natural Gas | Propane | Natural Gas, Propane | Natural Gas | Natural Gas | Natural Gas |
| Flow Rate | 11.1 GPM | 5.1 GPM | 5.1 GPM | not stated | Up to 6 GPM | 11.0 GPM | 9 GPM |
| BTU | 199k BTU | 120,000 BTU | 120,000 BTU/hr | not stated | 114,000 BTU | not stated | not stated |
| Installation Location | Indoor/Outdoor | not stated | Indoor | Indoor | Indoor | Indoor | Outdoor |
| Voltage | not stated | 120V | not stated | not stated | 120V | not stated | not stated |
| Temperature Control | not stated | 95°F–149°F, ±1°F | 95°F to 149°F | not stated | 90°F to 140°F | not stated | not stated |
| Certification | not stated | ANSI Z21.10.3 | not stated | not stated | not stated | not stated | not stated |
| Dimensions | not stated | 22 × 14.2 × 6.4 in | 9.25 x 20.2 x 20.2 inches | 45.3 x 19.5 x 19.5 in | 21"H x 13"W x 7"D | 28.7 x 17.3 x 14.8 inches | 33.9 x 14.8 x 22.1 inches |
| Use | not stated | not stated | not stated | Commercial, Boiler | not stated | not stated | not stated |
| Venting Type | Condensing | Condensing | Condensing | Condensing | Condensing | Condensing | Condensing |
| Weight | 55 pounds | 26 pounds | not stated | 79.4 pounds | 26 pounds | not stated | 71 pounds |
| Size | 11.1 GPM | not stated | 5.1GPM, 120,000BTU, LPG | 175K BTU / DHW 199K BTU | not stated | 11 GPM | 9 GPM |
| Color | Silver | Gray | Condensing | Gray | Silver | Gray | Outdoor Installation |
| Model | RX199iN | RH12KG-C-NG | RH12KG-C-LPG | IP175199C | CZ480NG | RTGH-RH11DVLN | RU160eN |
If you also need drinking water treatment, compare apec water tankless reverse osmosis water alternatives for kitchen filtration.
Frequently asked questions
Which alternative offers the highest flow rate for large households?
The Rinnai 11.1 GPM Condensing Dual-Fuel Water Heater provides the highest capacity. It delivers 11.1 gallons per minute, matching the original unit. This model is best for large homes needing simultaneous hot water. It features condensing venting and weighs 55 pounds.
What is the most compact option for indoor installation?
The Ranein 5.1 GPM Condensing Natural Gas Water Heater is the most compact. It measures 14.2 inches wide and 22 inches high. Weighing only 26 pounds, it is lighter than the Rinnai RX199iN. It is designed for indoor use with low elevation requirements.
Which unit is suitable for outdoor whole-home hot water?
The Rinnai RU160eN 9 GPM Outdoor Natural Gas heater is built for outdoor use. It delivers 9 GPM for whole-home coverage. The unit measures 22.1 inches long and weighs 71 pounds. It suits buyers with outdoor space who prioritize flow rate over a compact indoor footprint.
Is there a combi boiler option for space heating?
The Rinnai I-SERIES Plus Condensing Combi Boiler handles both space heating and hot water. It outputs 175K BTU for heating and 199K BTU for domestic water. It is larger, measuring 45.3 inches high. This model fits users who value smart controls and combined heating capabilities.
Which alternative is best for propane users?
The VancEpic 5.1 GPM Propane Condensing Water Heater is designed for propane. It delivers 5.1 GPM with 120,000 BTU output. The unit is compact, measuring 9.25 inches high. It is ideal for small propane-powered indoor installations where space is limited.
Which model offers the best balance of flow and efficiency?
The Thermomate 5.28 GPM Indoor Natural Gas heater balances flow and efficiency. It provides 5.28 GPM with condensing technology. Measuring 13.8 inches wide, it offers a compact footprint. This unit fits homes prioritizing digital control and efficiency over smart connectivity features.
What is the best high-flow indoor alternative to Rinnai?
The Rheem Prestige 11 GPM Condensing Water Heater offers robust indoor flow. It delivers 11 GPM for busy households. The unit measures 14.8 inches long and 28.7 inches high. It suits users who prioritize high capacity and smart programming over a compact size.